Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6ddd4ab753013b22…

MALICIOUS

RTF / .DOC

24.3 KB First seen: 2022-11-16
MD5: 4f610c59e24f023f6618f3b28239eb0b SHA-1: e5f62df42a683e460d37732fd9c2ce49c96a22c5 SHA-256: 6ddd4ab753013b22ec013f54588bddfce8dfe52d27aac8cbea2a5657c43e4fa1
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document that contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The ".objupdate" directive forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing', which is a common technique for malware droppers to bypass security settings. No scripts were extracted, and the embedded object itself is the primary indicator of compromise.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000047ca.bin
2871f571946cb16eeb894ff92c7a559224caab11ff00abc3de8cc6c18bba33fa
rtf-objdata-decoded RTF \objdata at offset 0x47CA 1408 bytes